Urea derivatives of2-aminobenzothiazoles

ABSTRACT

COMPOUNDS HAVING THE FOLLOWING STRUCTURE:   2-(R1-N(-R2)-CO-NH-),4-R3,5-R4-BENZOTHIAZOLE   WHEREIN R4 MAY BE HYDROGEN WHEN R3 IS SELECTED FROM THE FOLLOWING: C1 TO C6 STRAIGHT OR BRANCHED ALKYL, C3-C6 AKENYL, C3-C6 ALKYNYL, C3-C8 CYCLOALKYL, C1-C6 ALKOXY, C1-C6 ALKYLTHIO, C1-C8 MONO- OR C2-C8 DIALKYLAMINO, C1-C4 ALKYLSULFOXY, C1-C4 ALKYLSULFONE. THESE GROUPS MAY BE OPTIONALLY SUBSTITUTED BY HALOGEN, C1-C4 ALKOXY, C1-C4 ALKYLTHIO, CANO OR NITRO. IN ADDITION, R3 MAY ALSO BE SELECTED FROM THE FOLLOWING: FLUORO, CHLORO, BROMO, HYDROXY, CYANO, AMINO, MERCAPTO, OR PERHALOALKYL. WHEN R4 IS NOT HYDROGEN, IT MAY BE THE SAME OR DIFFERENT THAN R3 AND MAY BE ONE OF THE GROUPS EUMERATED ABOVE FOR R3. FOR THE PURPOSE OF THIS INVENTION R1 AND R2 ARE SELECTED FROM THE FOLLOWING GROUPS, C1-C6 STRAIGHT OR BRANCHED ALKYL, C3-C6 ALKENYL, C3-C6 ALKYNYL, C1-C6 ALKOXY OR C3-C8 CYCLOALKYL. THESE GROUPS MAY BE OPTIONALLY SUBSTITUTED BY HYDROGEN, C1-C4 ALKOXY, C1-C4 ALKYLTHIO, CYANO, OR NITRO. IN ADDITION, R1 AND R2 MAY COMPRISES TOGETHER A RING FROM 3 TO 8 ATOMS.

United States Patent 3,714,177 UREA DERIVATIVES OF Z-AIVIINOBENZO-THIAZOLES John E. Engelhart, Westfield, N.J., assignor to Esso Researchand Engineering Company No Drawing. Filed Apr. 9, 1970, Ser. No. 27,101Int. Cl. C07d 91/46 U.S. Cl. 260305 17 Claims ABSTRACT OF THE DISCLOSURECompounds having the following structure:

wherein R may be hydrogen when R is selected from the following: C to Cstraight or branched alkyl, C -C alkenyl, C -C alkynyl, C -C cycloalkyl,C -C alkoxy, C -C alkylthio, C -C monoor C -C dialkylamino, C -Calkylsulfoxy, C -C alkylsulfone. These groups may be optionallysubstituted 'by halogen, C -C alkoxy, C C alkylthio, cyano or nitro. Inaddition, R may also be selected from the following: fiuoro, chloro,bromo, hydroxy, cyano, amino, mercapto, or perhaloalkyl. When R is nothydrogen, it may be the same or different than R, and may be one of thegroups enumerated above for R For the purpose of this invention R and Rare selected from the following groups, C -C straight or branched alkyl,C -C alkenyl, C -C alkynyl, C -C alkoxy or C C cycloalkyl. These groupsmay be optionally substituted by halogen, C -C alkoxy, C -C alkylthio,cyano, or nitro. In addition, R and R may comprise together a ring from3 to 8 atoms.

This invention relates to novel, herbicidally efi'ective compounds. Inone aspect, this invention relates to urea derivatives ofZ-aminobenzothiazoles. In another aspect, this invention relates toderivatives of 2-aminobenzothiazoles as post-emergent herbicides.

It has been previously described in German Pat. No. 1,204,015 issued toFarbenfa'briken Bayer Aktiengesellschaft Company that substituted thioureas having the NH-C-R Y wherein X represents hydrogen, halogen and analkyl group having 1 to 2 carbon atoms; .R represents hydrogen, analiphatic group containing 1-6 carbon atoms and hay- ICC ing halogen oralkoxy substituted therein; and Y represents either oxygen or sulfur,possess herbicidal activity. These compounds are described in FrenchPat. 1,372,103- assigned to Farbenfabriken Bayer Aktiengescllschaft.

In addition, E. I. du Pont de Nemours & Company of Wilmington, Del. hasdisclosed in U.S. Pat. No. 2,756,135 compounds represented by thefollowing formula:

wherein R is hydrogen or a monovalent aliphatic hydrocarbon radical ofless than 5 carbon atoms and R is hydrogen or methyl. These compoundsare claimed as herbicides.

Consequently, it is observed that certain benzothiazole amides and ureashave herbicidal activity and that the art is constantly looking for newcompounds which display crop tolerance in this area.

The herbicidally active compounds of the subject invention arederivatives of Z-aminobenzothiazoles and more particularly, thecompounds of the invention are represented by the following formula:

0 R1 t in wherein R may be hydrogen when R is selected from thefollowing: C to C straight or branched alkyl, C -C alkenyl, C -Calkynyl, C -C cycloalkyl, C -C alkoxy, C C alkylthio, C -C monoor C -Cdialkylamino, C -C alkylsulfoxy, C -C alkylsulfone. These groups may beoptionally substituted by halogen, C -C alkoxy, C -C alkylthio, cyano ornitro. In addition, R may also be selected from the following: fluoro,chloro, bromo, hydroxy, cyano, amino, mercapto, or perhaloalkyl. When Ris not hydrogen, it may be the same or different than R and may be oneof the groups enumerated above for R For the purpose of this invention Rand R are selected from the following groups, C -C straight or branchedalkyl, C -C alkenyl, C -C alkynyl, C -C alkoxy or C -C cycloalkyl. Thesegroups may be optionally substituted by halogen, C -C alkoxy, C -Calkylthio, cyano or nitro. In addition, R and R may comprise together aring from 3 to 8 atoms.

These compounds are unique in that if a substituent is positioned at the4-position on the benzene ring, the compounds exhibit excellentherbicidal properties and in fact do demonstrate crop tolerance.Likewise, if substituents are present at the 4 and 5 position, thecompounds have excellent herbicidal properties together with croptolerance. However, if the substituent is positioned at the 5 positiononly, good herbicidal activity but poor crop tolerance results. If the Rgroup is positioned in the 6 or 7 positions, there is little or noherbicidal activity. This action is completely unexpected in view of thefact that in the above-described prior art, the substituted amides showthat one should expect good activity with a substituent group on any orall positions on the benzene ring.

It is not obvious from the prior art that compounds with substituents onthe 4 or the 4 and 5 positions on the ring would possess excellentherbicidal activity while exhibiting outstanding tolerance to certaincrops.

When the active compounds are applied for weed con- R3 trol in cottonfields, genuine selectivity occurs. Even at 3 rates of application muchhigher than needed to control R4 NaOH R4 N or destroy mature weeds thereis no adverse eifect to the I I I cotton plants. However, if thesuhstituents on the ring 5 NHIHBr NH2 system are in the 6 or 7positions, all selectivity and/or activity ceases. Exemplary ofcompounds falling within Step3 R the scope of the structure set forthhereinabove are as I 0 follows: R4 --N CH3) g 01 S NH:

a Compound 1 1,1-dimethyl-3-(4-methyl-2-benzothiazolyl)urea. I O1,1-dlmethy1-3-(4-ethyl-2-benzothiazolyl)urea. I II1,1-dimethyl-3-(4-methoxy-2-benzothiazolyl)urea. /NH N(CH3)21,l-dimethyl-3-(Methoxy-2-benzothiazo1yl)urea. N1,l-gimetlfiyI-g-Ii-n-propyli2blenzothfiazolylFree. 1 1- imet-isopropyenzo iazoy urea.liI-gimeglllgll-g-i-gigautygif-lfgngothiafiolyblluiea. Alternatively,the thiourea of Step 1 can be prepared by 1, ime yime yenzo azoy urea.l,l-dimethyl-li-(4 chlorobenzothiazalyl)urea. the followmg sequence1,1dimethyl3-(4-methyl-5-chloro-2-benzothiazolyl)urea. Step 1a R3 R3l,l-dimethyl-B-(4,5-dimethoxy-2-benzothiazolyl)urea. I1,1di1nethyl-3-(4-trifluoromethy1-2-benzothiazolyl)urea. S1,1-dimethyl-3-(4fiuoro-2-benzothiazolyl) urea. R 4 II R I S1,l-dimethyl-3-(4-methylthio-Z-benzothiazolyl)urea. 121,1-dimethy1-3-(4-cyano-2-benzothiazolyl)urea.1,1-dimethyl'3-(4-bromo-2J3enzothiazolyl)urea. c o o o m 1,1-dimethyl-3-(4dimethylamino-2-b enzothiazolyDurea. Hz 01,1-dimethyl43-(4-hydroxy-2-benzothiazoly1)urea. 1,1-d imethyl-B-(4-ethyl'5-methy1-2-benzothiazolyl) urea. S t 1b R R1,l-diethyl-3-(4-methyl-2-benzothiazolyl)urea. BP 3 I 3 S1#:giegfiyI-g-Eiethg-Z-begngothiaglyl)1113a. g 1,1 ie y-- me oxy enzoiazoy urea. 1-methyl-1-methoxy-3-(4-methyl-2-benzothiazolyl)urea. R4N13! R4 NH NHI 1-methyl-1-methoxy-3-(4-methoxy-Z-benzothiazolyl)urea.

25- l-methyl-1-methoxy-3-(4-ethyL2-benzothiazolyl)urea.

26- l-methyl-l-methoxy-3-(4,fi-dimethyl-Z-benzothiazolyl urea. y v1- yot i o y The ureas of Step 3 can also be prepared by alternate routes asfollows: Step 3a Rs (1) C001: 1'13 The compounds of this invention canbe prepared by (2) Well-known methods, examples of which are outlined RP4- schematically as follows: 40

7 i RiRzNHA R NH2 NHINCS R NHH/NIIZ H01 Step H20 3 Step 1 wherein R is alower alkyl group of C -C and R R R and/ or R are the same as definedpreviously.

REACTION CONDITIONS FOR SYNTHESIZING COMPOUNDS OF THE INVENTIONPreferred temp. (temp. Alternate range) Step Starting material Preferredreagents reagents Solvents 0. Pressure 1 1 mole, substituted aniline-1-2 moles ammonium KSCN. NaSCN; Water; nonprotic solvents 25150Atmospheric thiocyanate, 1 mole H01. H2804. to 10 atm. 2 Tliiourea 1mole Bromine 1 mole SOzClz, C12 Chlortofornll or gther non- 20100Atmospheric.

pro 10 so ven 3 1 Substituted 2-amin0benzo- 1-1.5 moles dimethyl Othercarbamoyl Pyridines or non-protic -20100 Do.

thiazole 1 mole. carbamoylchloride. halides. solvent. la-lb- 1 mole,substituted aniline. 1 mole thiophosgene, 2-10 Water, chloroform 550 Do.

moles ammonia. 3a- 1 mole, substituted Z-amino- 1 mole phosgene, l-10moles Other secondary Benzene, other non-protic 0-100 Atmosphericbenzothiazole. dimethylamine. amines. solvents. to 10 atm. 31)Substituted Z-aminoben- 11.5 moles alkyl chlorofor- .-..d0 do 25-200Atmospheric zothlazole 1 mole. mate, 1-10 moles dito atm.

methylamine.

i mp o needed I p al resu t The 2-aminobenzothiazole derivatives ofthe-invention have general herbicidal properties. They are especiallyuseful in certain types of weed control, such as for example, anapplication to crop lands to give control of the common weeds withoutharming the crop plants, particularly cotton.

The herbicidal compositions of the invention are prepared by mixing oneor more of the Z-aminobenzothiazoles defined hereinabove in herbicidallyeffective amounts with a conditioning agent of the kind used andreferred to in the art as a pest control adjuvant or modifier to provideformulations adapted for ready and efficient application to weeds (i.e.unwanted plants) using conventional applicator equipment.

Thus, the herbicidal compositions or formulations are prepared in theform of solids or liquids. Solid compositions are preferably in the formof wettable powder or dust and are compounded to give homogeneousfree-flowing dust by admixing the active compound or compounds withfinely divided solids, preferably talcs, natural clays, pyrophylite,diatomaceous earth, or flowers, such as walnut shell, wheat, redwood,soya bean, cottonseed flowers, and other inert solid conditioning agentsor carriers of the kind conventionally employed in preparing pestcontrol compositions in dust or powdered forms.

Liquid compositions of the invention are prepared in the usual way byadmixing one or more of the 2-aminobenzothiazoles with a suitable liquiddiluent medium. With certain solvents, such as alkylated naphthalene,dimethylformamide, and cresol, relatively high concentrations of theureas can be obtained in suspension or solution.

The herbicidal compositions of the invention, whether in the form ofdust or liquids, preferably also include a surface active agent,sometimes referred to in the art as a wetting, dispersing or emulsifyingagent. These agents, which will be referred to hereinafter more simplyas surface-active dispersing agents cause the compositions to be easilydispersed in water to give aqueous sprays which for the most part,constitute a desirable composition for application.

The surface-active dispersing agents employed can be of the anionic,cationic, or nonionic type and include, for example, sodium andpotassium oleate, the amine salts of oleic acid, such as morpholine anddimethylamine oleates, the sulfonate animal and vegetable oils, such assulfonated fish and castor oils, sulfonated petroleum oils, sulfonatedacyclic hydrocarbons, sodium salt of lignin sulfonic acid (goulac),alkyl naphthalene sodium sulfonate, sodium salts of sulfonatedcondensation products of naphthalene and formaldehyde, sodium laurylsulfate, disodium monolauryl phosphate, sorbitol laurate,pentaerythritol monostearate, glycerolmonostearate, diglycol oleate,polyethylene oxides, ethyl oxide condensation products with stearylalcohol and octylphenol, polyvinyl alcohols, salts, such as the acetateof polyamines from reductive amination of ethylene-carbon monoxidepolymers, lauryl amine hydrochloride, lauryl piperidinium bromide,stearyltrimethylammonium bromide, cetyldirnethylbenzyl ammoniumchloride, lauryl dimethyl amine oxide, and the like. Generally, thesurface-active agent will not comprise more than about 5 to by weight ofthe composition and in certain compositions the percentages will be 1%or less. Usually, the minimum lower concentration will be 0.1%.

The herbicidal compositions are applied either as a spray or a dust tothe location to be protected from undesirable plant growth, commonlycalled weeds, i.e., plants growing where they are not wanted. Suchapplication can be made directly upon the area and the weeds thereon,during the period of weed infestation in order to destroy the weeds.Thus, the compositions can be applied as aqueous foliar sprays, andalternatively, the dry powder composition can be dusted directly on theplants.

In applying the herbicidal compositions of the invention for selectiveweed control as in the control of weeds in cotton or corn fields, thecompositions are preferably applied after emergence of the seedlings. Inother words, the applications are of the post-emergence type.

The active compound is, of course, applied in an amount sufficient toexert the desired herbicidal action. The amount of the active compoundpresent in the compositions as usually applied for destroying orpreventing weeds will vary with the manner of application, theparticular weed for which control is sought, the purpose for which theapplication is being made and like variables. In general, the herbicidalcomposition as applied in the form of a spray or a dust, will containfrom about 0.5% to by weight of the 2-aminobenzothiazole derivative.

Fertilizer materials, other herbicidal agents and other pest controlagents, such as insecticides and fungicides can be included inherbicidal compositions of the invention if desired.

In order that the invention may be better understood, the followingexamples are given in addition to the examples already givenhereinabove. The examples illustrate a method for making compounds ofthe invention, herbicidal formulations employing such compounds,herbicidal applications and the results obtained. Parts are by weightunless otherwise specified in the examples, and the numbers followingtabulated ingredients in the examples represent parts by weight of theingredients of such compositions.

EXAMPLE 1 Preparation of 2-amino-4-methylbenzothiazole Into a 500 ml.4-necked flask equipped with magnetic stirrer, condenser, thermometerand additional funnel, was added 16.6 g. (0.1 mole) o-tolylthiourea andml. chloroform. To this mixture was added over a 25 minute period, 16.0g. (0.1 mole) bromine dissolved in 50 ml. chloroform during which timethe temperature rose to 42 C. The solution was then heated to reflux forthree hours, cooled and filtered to yield 12.2 g. of hydrobrornide salt.The salt was digested with 100 ml. 10% sodium bisulfite for 30 minuteson a steam bath and then made basic with 10% sodium hydroxide solution.After cooling, the white granular solid was filtered to yield 9.7 g. ofthe title compound, M.P. 135.5-137".

EXAMPLE 2 Preparation of 1,1-dimethyl-3-(4-methyl-2-benzothiazolyl)ureaInto a 250 ml. flask equipped with magnetic stirrer, condenser,thermometer and addition funnel, was added 50 ml. pyridine and thencooled to 5 C. To the pyridine was added dropwise 8.9 g. (0.083 mole)dimethylcarbamoyl chloride and, in small batches, 12.3 g. of 2-amino-4-methylbenzothiazole, keeping the temperature below 15. After stirring atroom temperature for one hour, the mixture was heated at 70 for 20minutes, cooled, and poured into 200 ml. of water. The solid product wasfiltered and dried in vacuo to yield 15.5 g. of white granular solid,M.P. 168-1745". Recrystallization from benzene yielded colorlesscrystals, M.P. 176.5178.

Calculated for C I-1 N 05 (percent): C, 56.3; H, 5.53; N, 17.85. Found(percent): C, 56.8; H, 5.70; N, 17.70. The structure was confirmed byNMR and IR.

EXAMPLE 3 reparation of 1,1-dimethyl-3-(4-ethyl-2- benzothiazolyl ureaUtilizing the procedure of Example 2, 10.5 g. of urea 2 was preparedfrom 8.5 g. (0.05 mole) 2-amino-4-ethy1- benzothiazole.Recrystallization from benzene yielded product of M.P. 158l60.

Calculated for C H N OS (percent): C, 57.8; H, 6.02; N, 16.8. Found(percent): C, 57.2; H, 6.06; N, 16.1.

7 EXAMPLE 4 Preparation of1,1-dimethyl-3-(4-methoxy-2-benzothiazolyl)urea Utilizing the procedureof Example 2, 8.8 g. of urea 3 as a dihydrate was prepared from 9.0 g.(0.05 mole) of 2- amino-4-methoxybenzothiazole, M.P. 101-105.5.

Calculated for C H N O S'2H O (percent): C, 46.0; H, 5.93; N, 14.7.Found (percent): C, 46.2; H, 6.02; N, 14.7.

EXAMPLE 5 Preparation of 1,1-dimethyl-3-(4,5-dimethyl-2- benzothiazolyl)urea Utilizing the procedure of Example 2, 3 g. of urea 8 were preparedfrom 6.6 g. (0.037 mole) 2-amino-4,5- dimethylbenzothiazolc, M.P.149.5-151.

Calculated for C H N S (percent): C, 57.8; H, 6.03; N, 16.8. Found(percent): C, 56.4; H, 5.86 N, 16.0.

EXAMPLE 6 Preparation of 1,1-dimethyl-3-(4-chlorobenzothiazolyl) ureaUtilizing the procedure of Example 2, 17.8 g. of urea 9 were preparedfrom 18.5 g. (0.1 mole) of 2-amino-4- chlorobenzothiazole, M.P. 177-183Calculated for C H ClN OS (percent): C, 46.8; H, 3.91; N, 16.4. Found(percent): C, 46.2; H, 3.42; N, 15.8.

EXAMPLE 7 Preparation of an 80% wettable powder formulation of1,l-dimethyl-3-(4-methyl-2-benzothiazolyl)urea 85% of 1,1 dimethyl3-(4-methyl-2-benzothiazolyl) urea (95 purity), of a complex polymerizedorganic salt'of a sulfonic acid of. the alkyl aryl type known as DarvanI and manufactured by the R. T. Vanderbilt Chemical Company of 230 ParkAvenue, New York, 6% of sodium alkyl naphthalene sulfonate known asNekal BX78 manufactured by the Antera Division of General Aniline andFilm Co., and 4% of a hydrated silica known as Hi-Sil 233, manufacturedby the Pittsburgh Plate Glass Company, were blended together and themixture ground to an average particle size of 5 to microns.

EXAMPLE 8 Representative benzothiazole urea derivatives from thoseprepared in the previous examples were evaluated for post-emergentherbicidal activity in this example. The test procedure employed was asfollows:

alfalfa, corn, rice and oats) and six weeds (mustard, morning glory,Zinnia, crabgrass, barnyard grass and foxtail) were sprayed with aformulation containing the test chemical and acetone as solvent, at aseries of rates beginning at ten pounds per acre. The flats were thenheld in the greenhouse and a response rated after 12 to 16 days. Theresponse was rated by a scale of 0 to 10. (The 0-10 scale is defined asfollows:)

0=no injury 13=slight injury 46:moderate injury, plants may die7-9=severe injury, plants will probably die 10=all plants dead (completekill) In order to prove the criticality of the positioning of oursubstituents on the rings, the following compounds were compared withthe compounds of the subject invention. These compounds neitherconstitute a part of this patents disclosure nor are encompassed in theclaimed subject matter.

Compound No.

28 1,1-dimethyl-3-(2-benzothiazolyl)urea.

- 1,1-dimethyl-3-(5-methyl-Z-benzothiazolyl)urea.

Table I illustrates the unique cotton tolerance of Compounds 1, 2, 3 vs.the analogous, patented Compound 28, which shows no cotton tolerance.

Table II shows the effect of moving a functional group outside the areaof this patent. The S-methyl derivative, Compound 29, shows no cottontolerance whereas the 4-methyl isomer, Compound 1, claimed in thesubject application is a selective herbicide. Likewise, the 1,3-dimethyl urea, Compound 30, shows no cotton tolerance shown by1,1-dimethyl isomer, Compound 3, also claimed in the subjectapplication. Compounds 32 and 33, the 4,7-disubstituted isomers, as wellas the 6-substituted type, Compound 34, show no herbicidal charactereven at the 5 or 10 lb./acre application rate.

Table III dramatically illustrates the unique degree of cotton toleranceexhibited by compounds of this invention, namely Compounds 1 and 3 inthis case. The complete lack of cotton tolerance of the previouslypatented Compound 28 is also vividly demonstrated. The lack of injury tocotton even at the extremely high rate of 32 lbs/acre with Compounds 1and 3 points to the utility Two flats seeded with six crops (cotton,soybean, of these new compounds.

TABLE I.BENZOTHIAZOLE UREAS Post-emergence Barn- Morn- Rate, yard CrabFox- Musing Cot- Soy Compound lb. grass grass tail Zinnia tard glory tonbean Alfalfa Corn Rice Oats Post-emergence 10 10 9 10 10 10 10 0 10 9 510 9 10 10 10 10 10 1 n? .f 10 10 10 10 10 10 10 1 10 7 7 9 5 10 10 10I0 10 10 10 5 10 10 9 9 8 Test 2 TABLE II.BENZOTHIAZOLE UREAS Barn-Rate, yard Crab Fox- Mus- Cot- Soy ii i g Compound lb./a grass grasstall Zinnia turd ton bean Alfalfa Corn Rice Oats glory TABLE III.POSTEMER GENCE DATA Barnyard Morning Cotton grass glory Conc., Compound1b./a. A B A B A B NOTE.Column A Phytotoxicity rating; Column BHarvested fresh Weight of crop or weed (in grams).

What is claimed is: 1. Compounds of the formula wherein R represents C-C alkyl; R represents C -C alkyl or C -C alkoxy; R represents C -Calkyl, C -C alkoxy, C C. alkylthio, fluorine, chlorine, bromine,trifiuoromethyl, or cyano; and R represents hydrogen, C -C alkyl, C -Calkoxy, or chlorine.

2. A compound according to claim 1 which is, 1,1-dimethyl-3-(4-rnethyl-2-benzothiazolyl urea.

3. A compound according to claim 1 which is,1,1-dimethyl-3-(4-ethyl-2-benzothiazolyl)urea.

4. A compound according to claim 1 which is,1,1-dimethyl-3-(4-methoxy-2-benzothiazolyl)urea.

5. A compound according to claim 1 which is,1,1-dimethyl-3-(4-ethoxy-Z-benzothiazolyl)urea.

6. A compound according to claim 1 which is, 1,1-dimethyl-B-(4-n-propyl-2-benzothiazolyl) urea.

7. A compound according to claim 1 which is,1,1-dimethyl-3-.(4-isopropyl-2-benzothiazolyl)urea.

8. A compound according to claim 1 which is, 1,1-dimethyl-3-(4-n-butyl-Z-benzothiazolyl urea.

9. A compound according to claim 1 which is, 1,1-dimethyl-3- (4,5-dimethyl-2-benzothiazolyl urea.

10. A compound according to claim 1 which is,1,1-dimethyl-3-(4-chlorobenzothiazolyl)urea.

11. A compound according to claim 1 which is, 1,1-dimethyl-3-4-methyl-5-chloro-2-benzothiazolyl urea.

12. A compound according to claim 1 which is, 1,1-dimethyl-3-(4,5-dimethoxy-Z-benzothiazolyl urea.

13. A compound according to claim 1 which is, 1,1-dimethyl-3-(4-trifluoromethy1-2-benzothiazolyl urea.

14. A compound according to claim 1 which is, 1,1-dimethyl-3-(4-fluoro-2-benzothiazolyl urea.

15. A compound according to claim 1 which is, 1,1-dimethyl-3-(4-methylthio-2-benzothiazolyl)urea.

16. A compound according to claim 1 which is,1,1-dimethyl-3-(4-cyano-2-benzothiozolyl)urea.

17. A compound according to claim 1 which is,1,1-dimethyl-3-(4-bromo-2-benzothiazolyl)urea.

References Cited UNITED STATES PATENTS 7/1956 Searle 260-305 12/1970Zakaria 260--305 Fujikawa et al., Chem. Abstracts, 70:77857n (1969).Moore, Chem. Abstracts, 67164387): (1967).

5 ALEX MAZEL, Primary Examiner R. J. GALLAGHER, Assistant Examiner US.Cl. X.R.

